Synthesis of SnO2/Fe2O3 thin films for efficient photocatalytic degradation of methylene blue under sunlight

This study discusses the surface effect of SnO2 and SnO2/alpha-Fe2O3 thin films prepared using the spray pyrolysis technique on the photocatalytic degradation of methylene blue MB under sunlight irradiation for different times. These layers were examined using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) to determine their structural composition and morphological characteristics. X-ray diffraction shows that SnO2 thin films crystallize in a tetragonal structure with a preferential orientation along to (110), while SnO2/alpha-Fe2O3 multilayer crystallizes in a rhombohedral structure of alpha-Fe2O3, with the presence of some pick of the tetragonal SnO2. In addition, the grain size decreases from 48 nm for SnO2 thin films to 42 nm for SnO2/alpha-Fe2O3. It was also discovered that SnO2/alpha-Fe2O3 exhibits much improved photocatalytic performance with the degradation rate compared to SnO2 thin layer, which can be related to the surface roughness and crystallite size evaluated by XRD and SEM.